Kusanagi-no-Tsurugi, is one of the three
Go-Shin Tai of the Japanese
Empire, one of the three
sacred treasures that symbolize the
Imperial throne. The sword was taken from the
Dragon-King of the sea by
Yamata no Orochi, who lost it later when
Susanoo removed it from his tail. Because it is one of the Go-Shin Tai, it can only be weilded by the
Emperor of Japan. The sword was
lost sometime in the 12th
century.
The sword's original name was Ama-no-Murakumo-no-tsurugi, which means "heavenly gathering of clouds sword." It recieved its current name, "Grass Cutting Sword" when it was used by Yamato Takeru to cut grass to make an escape route and shield him from surrounding fire in one of the Ainu subjugation campaigns.